Dental bur and excavator.



N0. 843,273. PATENTED FEB. 5, 1907.

W. HOMANN.

DENTAL BUR AND EXGAVATOR.

APPLICATION FILED MAR.29, 1905.

v ,4 rromvsrs "I: NORRIS PETERS ca, wAsmNur N, n c

UNITED @TATES aren't rrren.

DENTAL BUR AND EXCAVATOR.

Specification of Letters Patent.

Patented Feb. 5, 1907.

Application filed March 29,1905. Serial No. 252,621.

ing at Dusseldorf, Germany, have invented certain new and useful Improvements in Dental Burs and Excavators, of which the following is a specification, such as will enable those skilled in the art to which it appertains to make and use the same.

This invention relates to dental burs; and. the object thereof is to provide an improved device of this class which may be used as an ordinary bur and for excavating a tooth and also as a drill and for trimming or cutting the outer edges or corners of teeth and forvarious other purposes; and with this and other obj eets in view the invention consists in a device of the class specified constructed as hereinafter described and claimed.

The invention is fully disclosed in the following specification, of which the accompanying drawings form a part, in which the separate parts of my improvement are designated by suitable reference characters in each of the views, and in which Figure 1 is a perspective view of a dentistbur made according to my invention; Fig. 2, an end view thereof.

In the practice of my invention I provide a dentist-bur comprising a spherical head portion (1-, having the usual shank b, that portion of which adjacent to the head and forming the neck of the bur is slightly reduced in size, as shown at c, and said head portion is substantially spherical in form and provided with longitudinally and spirally arranged ribs (1, which are extended along and around the neck portion 0 of the shank b to a predetermined point on said shank. The ribs dare of greater transverse depth on the head portion a than on the shank b and the neck portion 0 thereof, and the faces of these ribs on one side are in a plane passing centrally through the head a, while the opposite faces thereof are beveled or inclined at an angle of Germany, and resid of approximately forty-five degrees. This l shape of the ribs (Z in cross-section is the same on the shank and neck portion 0; but the l transverse depth of said ribs on these portions is slightly less than on the head a, as hereinbefore described. 1 The edges of the ribs (Z from the central transverse portion of the head a to the ends i of ribs on the shank Z) are provided with notches or recesses c, forming corresponding teethf, and my improved bur is particularly designed for excavating teeth, but may also f be used conveniently as a drill, and by forming the ribs (Z onthc shank b and on the nec portion 0 thereof the device is particularly adapted for use in rimming out the entrance I to a cavity or recess excavated in a tooth, and by reason of the teeth f these ribs also l adapt the device for use in cutting oil or reducing the edges or corners of a tooth.

In the drawings forming part of this specification the various figures are on a much ens larged scale, and it will be understood that l my improved bur is in practice of the usual 1 dimensions. l Having fully described my invention, what I I claim as new, and desire to secure by Letters Patent, is

A. dentist-bur, comprising a spherical head provided with a reduced shank or neck portion, the curve between the head and the L shank or neck portion being gradual, said l head and shank or neck portion being provided with longitudinally and spirally ar ranged cutting-ribs having serrations or teeth except at the outer end of the head portion, l substantially as shown and described. I In testimony that I claim the foregoing as l my invention I have signed my name, in lpresence of the subscribing witnesses, this 14th day of December, 1904. t \VILLY IIOMANN. lVitnesses: i WILLIAM Essnnwnm, 1 PETER LIEBER. 

